The present invention relates to an improved fastener for securing a protective liner to the bed of a pick-up truck. In the use of protective liners for beds of pick-up trucks there have in the past been many different devices and suggestions of how to secure the liners to the beds. Examples of such devices and suggestions may be found in U.S. Pat. Nos. 4,595,229, 4,740,026, 4,796,942, 4,850,633 and 4,906,040.
Such devices involve the use of multi-part fasteners, from the very common screw nut assembly to a complicated bolt-ring-anchor locking member or fixture. Past designs also provided the beds and liners with special features, such as special openings and ridges, in which, the special openings provided in the beds created potential rust areas due to marking or scratching of the paint of the beds. Moreover, past devices required the use of tools to secure the fasteners and the fasteners many times did not have the capacity to accommodate different designs of beds.
A more recent design of a fastener appears in U.S. Pat. No. 5,046,775. The device shown in this patent relates to a one piece snap lock type fastener that is adapted to be inserted through a hole made in the liner and having a base plate that fits over the hole on the outside of the liner and a tongue that project into the hole. The outer peripheral surface of the tongue is formed with three distinct surfaces, namely a clamping surface, a cam surface and a locking surface. When mounted, the fastener is said to be locked between the clamping and locking surfaces which are provided in conjunction with the base plate with V-shaped throats to accommodate this purpose.